Arrangement in manufacturing of coated welding electrodes



Sept. 12, 1950 E. w. v 2,522,364

ARRANGEMENT IN MANU ACTURING OF I COATED DING ELECTRODES 7 File eb. '27, 1948 GRANA [N V EN TOR.

EIDS?" N Grand James Aiken A Home 1 Patented Sept. 12,1950 v,

" Ernst W. Grand, Ha'mmarbyhojden, Sweden; as-

" signor to Allmanna Svenska Elektriska'Aktie-' bolaget, Vasteras, Sweden, a

Sweden I Application Fermi-ya, 1948, Serial No. 11,436 1 corporation of.

Sweden February 12, 1944 semen Latte Law 690, August 8, i946 4 Patentexpires February 12,1964].

process is the .one preferred for quantityfproduc tionof coatedelectrodes. It has. the disadvantime in that it'is difficult to achieve a coating ofuniform thiclgnessjupon the wire because the wire, which varies in' diameter withinits toler-i ance of manufacture, does not move through the die concentric with the axis thereof and consequently some portions of the wire are more heavily coated'dh"'cineside thanon the other. Such, uneven. coating adversely. affects :the. use of the electrode during welding operations.-.

An objectof the instant invention is to produce a coating of uniform thickness'upon an electrodelcore wire being forced through an ex- Another object of the invention is to-produce an extruding .die. in which means are provided for holding the electrode core wire in concentric relationship with respect to the coating orifice of the die.

In the usual electrode coating die, a guide' sleeve is mounted rearwardly of the outlet die orifice, the axis of the sleeve being a1ignedwith the axis of the die opening. Means are provided for introducing coating material under high pressure about the wire as it leaves the guide sleeve, this coating material being extruded upon the surface of the wire as the wire is pulled through the die opening. Because the wireis not of uniform thickness throughout its length, the guide sleeve must be slightly larger than the maximum diameter of the wire so that the wire can be forced through the sleeve without binding therein. Consequently, when thinner sections of the wire pass through the sleeve, there is sufiicient play between the wire and the sleeve to allow the wire to be displaced with respect to the sleeve so that its axis is no longer concentric with that of the sleeve or of the die orifice. This displacement throws the Wire ofi center and results in an uneven coating being applied to the wire as it passes through the die orifice. In the instant invention, this displacement is avoided which:v

by using the press'urepf the coating composition as it enters the die press, to force the electrode core wire against one side of the guide sleeve, the wire beingv held. against this face of the sleeve re-, gardless of the diameter of the wire. The out-; let die orifice is then positioned so that itsaxis. is in alignment with the axis of the wire in its held position on the sleeve instead of being in. alignment with the axisof the guide sleeve.; Thus, as the wireis held against displacement in the guide-sleeve and in alignment with the axis of the die orifice, a uniform coating will be applied. tothe wire as itis pulled through the die. orifice regardless of the ,changeiin diameter. ofthewire. w r e The means by 'vvhich. -the. objects of the inven-j, tion are obtained are more fully described with. reference to the accompanying drawings, in.

truding die vpress,constructed accordingv to this} inventiomand, I Fig. ,2 is :a cross sectionalview along the line} 31-4 of Fig.1.

The diev press includes ;a housing I which, 'is. bored to receiveha .first ..sleeve 2 which is con-, tinued into an abrasive resisting guide sleeve 3 joined to. thesleeve 2- by.--mean s of bushing The forward end of the sleeve 3 is surrounded by a mouthpiece 5, and immediately adjacent this mouthpiece and the end of sleeve 3 is the extruding die 6. The outlet end of sleeve 3 extends to the plane of the outlet side of mouthpiece 5, and thus is substantially at the inlet side of the orifice in die 6. The diameter of the opening in die 6 of course determines the thickness of the coating composition on wire II. A coating compound 1 is adapted to be forced under highpressure' into the die opening from a chamber 8 which is located above sleeve 3. Between mouthpiece -5 and bushing 4 is an annular space 9 surrounding sleeve 3 into which the coating compound flows. On the side of the sleeve 3 adjacent chamber 8 is an opening III which is illustrated as a slot or channel extending inwardly from the outlet end of sleeve 3 perpendicular to the bore of sleeve 3, this slot allowing the coating composition to enter into the sleeve and press down upon the electrode wire H, thus forcing the wire H against the bottom of the inner surface of the sleeve.

The axis of the orifice in die 6 is mounted concentric With the axis of wire II when said wire is forced against the lower surface of sleeve Fig. 1 is across-sectional view throughanex-I and normally the clearance between the core wire H and the sleeves 2 and 3 will be at least from 0.2 to 0.3 mm. Conseguently, the wire 41 may be pulled through sleeves 52 and. 3 without undue friction. However, whenasmal-ler :sections of the core wire are pulled through the sleeves a suflicient play exists between the cone wireand sleeve 3, which would allow the coreiwiilie 11 01109 '1 displaced in the sleeve under the action of the pressure of the coating composition :1. displacement is prevented by means of the opening 4 sleeve furthest away from the axis of said die to allow the coating mass to exert a force on said wire through-said slot and toward the :axis of said 1116,.

2. A welding electrode coating device compris- 12mg a guide sleeve having an inner diameter [0 wherein the pressure of the (coating cernnosition is used to force core wire ll against the inner surface of .the sleeve whichis opposite the direction from which the pressure of the ,coating composition ;is being applied. This holds the wire I I sothat its axis-is uniformly substantially exactly aligned with the axis offthe die opening in die 6. This opening in the die "6 determines the final {thickness of the coating upon the wire, and the wire-is held steady and cent-rally of the opening as' it' is pulled throug-h die 45, a uniform coating is achieved upon the wire.

Having-now disclosed tlre means by which the objects of my invention have been obtained,

"1 claim-z 1. 5A welding e ec rode noting device comprising a core wire receiving sleeve with a bore at least aslar ge in diameter as the thickest part th "Wire, a coatin ma s extru in di inalignment with said sleeve close "to the exit end of said sleeve, said die "having an opening equal to the outer diameter of h o t d 61 t nde and ha ing an axis slig y di placed a lateral directionin relation to the axis of the bore of said sleeve, a su ly channel and an'annular chamber for the delivery of :the coating mass under pressure to the core wf-ire between greater than the maximum diameter of a core -,wire being guided through said sleeve, a housing enclosing said sleeve, means in said housing for tending thezcqating imposition to the core wire 1.130 fcoaited, a mitt-out portion in one side of said sleeve admitting the coating composition to the interior of the 'sleeve, and causing said com- :RQSitiQn.toiexerteaninnbalanced force on the core Mire audio-force said wire against the inner wall 0i said sleeve at the side thereof opposite to said zcut-;cu-t portign,' and a die adjacent to the outlet end of said sleeve and mounted eccentrically to said :fileeve.

3. A welding electrodeicoating device, comprising a core resenting sleeve nith a here at least as large in diameter-es .the thickest part of. the core wine, a heating mass extruding ,die

alignment with esaids'leevesclose to .the exit end of said sleeve, .said .dieghaving an opening equal to the outer diameterpf ,the coated electrode and having anaxis slightly .displaced .in a lateral direction in relatiQn to the axisof the bore .of said sleeve, vasupnly channel andan annular chamber for the .delivery v.oi the coating lmass launder pres sure to the .cpre wire hetweensaid sleeve and said iERNSI w. manna. znnnxinenens tQIT-ED The following references are n a cher?! in Number Name 1,633,620 Alderfer June 28, 1927 1377503985 "Kivley .a. July 722, 112930 23%;898 Gnuetjen .u.." 1,; 194*], 

